Preparation of Intellingent Catalysts by Means of Layered Host Compounds Structurally Modified with Guest Molecules

合成了新型主客体催化剂，在蒙脱石中插入了手性罗络合物和结构调谐客体，并观察到催化剂的催化性能随层间距和客体分子取向的变化而变化.制备了不同层间距的多重改性催化剂：结构调谐客体修饰蒙脱石，如伯胺和季胺(C_nH_&lt；2n+2&gt；NH_3^+(1ﾟC_n)，(C_NH_&lt；2n+2&gt；)_2(CH_3)_2NH_3~+(4ﾟC_n)分别具有0.37~1.07 nm(1ﾟC_n)和1.93~2.88 nm(4ﾟC_n)的间隙。(2)通过改变主体层电荷来控制客体分子的取向。(3)MMS：MMS催化剂对前手性烯烃和酮的不对称加氢反应具有较高的催化活性和选择性，在氢气压力为30atm时，其催化活性和选择性高于相应的均相催化剂。这些结果表明，MMS催化剂比均相催化剂更稳定。(4)层间距和客体取向对催化性能的影响：发现层间距和客体取向对催化活性和选择性有明显影响，在α-蒎烯加氢反应中，Rh-Diop/C_NN~+/NaHT(CS=2.46~2.78 nm)的转化率为1.3~7.3%，外选择性为50~70%，而Rh-Diop/C_NN~+/LiTN(CS=1.93~2.88 nm)的转化率高于99.8%，外选择性为92%。由于LiTN的层电荷密度是NAHT的三倍，LiTN中结构调谐客体(C_nN^+)的取向几乎垂直于硅酸盐层，而NAHT中的结构调谐客体(C_nN^+)的取向与层片成58~65度。特别是，这些客体取向肯定会影响催化剂的活性和选择性。

The novel host-guest catalysts (MMS), in which chiral rhodium complexes as well as structural tuning guests were intercalated into smectites, were synthesized, and drastic change in catalysis was observed depending on the interlayer spacing as well as the orientation of guest molecules.Preparation of multiple-modified catalysts (MMS) with various interlayer spacings : Smectites modified with structural tuning guests such as primary and quaternary ammoniums (C_nH_<2n+2>NH_3^+(1ﾟC_n), (C_nH_<2n+2>) _2 (CH_3)_2NH_3^+(4ﾟC_n), respectively) have clearance spaces (CS) of 0.37 -1.07 nm for 1ﾟC_n and 1.93-2.88 nm for 4ﾟC_n with changing n from 10 to 18. (2)Control of the orientation of the guest molecules by changing the layer charge of hosts. (3)Catalysis for the asymmetric hydrogenation of prochiral olefins and ketones by MMS : MMS catalysts show higher catalytic activity and selectivity than the corresponding homogeneous ones in the hydrogenation of alpha-pinene and acetophenones at 30 atm of H_2 pressure. These results indicate that MMS catalysts are more stable than the homogeneous ones. (4)Effect of the interlayer spacing and the guest orientation on the catalytic behavior : It is found that the interlayer spacing and the orientation of guests clearly affect the catalytic activity as well as the selectivity, In the hydrogenation of alpha-pinene, Rh-DIOP/C_nN^+/NaHT(CS=2.46-2.78nm) showed the conversions of 1.3-7.3 % with low exo-selectivity of 50-70 %, while Rh-DIOP/C_nN^+/LiTN(CS=1.93-2.88nm) showed much higher conversions over 99.8 % with high exo-selectivity of 92 %. Since LiTN has three times higher layer charge density than NaHT, the orientation of structural tuning guests (C_nN^+) in LiTN was nearly perpendicular to the silicate layer, while that in NaHT was in the range between 58 to 65 degree to the layer sheet. Particularly these guest orientations definitely affect the catalytic activity and selectivity.